When my Solder paste and Solder flux arrived in syringe packages, it was quite a hassle to dispense them because the plunger was to long. I thought about buying those fancy aluminum plungers but in the end, it was just the same and because I used them sparingly, again, the plunger would be an issue. Of course I can transfer the stuff to a new syringe and then that would solve my problem of over-stretching my thumbs. There are other solutions out there from better designed plungers to the electrical versions, where both are able to dispense accurate amounts but at Industrial prices.
I could DIY if I know how but again, all that time and money just to relax my thumb…
Three years later, I saw a new design which was more or less what I wanted. However, despite one vendor selling at the ‘correct’ price, I have to wonder. Due to the design where the bolt threads into the plastic, that gaping hole could be the weakest point, engineering plastics or not.

Squeeze, turn, squeeze, turn.
I suppose the double-action one day might come where you do not need to do anything by squeeze the handle.